Toll telephone switching apparatus



H. M. FRIENDLY AND A. E. BURNS. TOLL TELEPHONE swncmwe APPARATUS.

APPLICATION FILED JUNE I5, 1915.

Patepted June 1,1920

5 SHEETS-SHEET lw Q fifilllllijlm H. M. FRIENDLY AND ALE. BURNS. TOLL TELEPHONE SWITCHING APPARATUS.

APPLICATION FILED JUNE I5, I915- 1,34;2,260. PatentedJune 1, 1920.

5 SHEETS-SHEET 2.

Wrs W4; M waam.

H. M. FRIENDLY AND A. E. BURNS.

TOLL TELEPHONE SWITCHING APPARATUS.

APPLICATION FILED JUNE 15. 1915.

1,342,260. I Patented June 1, 1920.

5 SHEETS-SHEET 3.

APPLICATION FILED JUNE 15/1915- Patented June 1, 1920.

5 SHEETSSHEET 4- hefzfirs: %4V f W6. 8%

H. M. FRIENDLY AND A. E. BURNS. TOLL TELEPHONE SWITCHING APPARATUS.

APPLICATION FILED JUNE 15. I915.

Patented June 1, 1920.

5 SHEETSSHEET 5 9 wwa HERBERT M. FRIENDLY AND ARCHIBALD 'E. BURNS, OF PORTLAND, OREGON; SAID BURNS AS SIGNOR TO SAID FRIENDLY.

- TOLL TELEPHONE SWITCHING APPARATUS. O

Application. filed June 15,

To all whom it may concern:

Be it known that we, HERBERT M. FRIENDLY and ARCHIBALD E. BURNS, residents of Portland, Multnomah county, Oregon, have invented certain new and useful Improvements in Toll Telephone Switching Apparatus, of which the following is a specification. 7

Our invention relates to improvements in apparatus, circuit systems, and methods of operation in connection with toll telephone switching apparatus.

A feature of this invention is to provide means and methods whereby any one of three toll lines terminating or entering at an interconnecting or common point may each be connected .with any one of the remaining two lines through the agency of electromagnetic devices at, the said common point, actuated by current from remote stations on said lines under independent control of operators at said stations.

Further, a feature of our invention relates to the means and methods whereby the calling station may signal the called station by the well known method of so called ringing, or other means.

Further, a feature of our invention relates to means whereby signals are displayed at a common point to indicate to the operator at the said common point the fact that a through switch or service is being made between two of the lines entering said common point, and to especially indicate which lines are interconnected thus.

Further, a feature of our invention provides for introducing a repeating coil by automatic process when any predetermined line is interconnected with another line.

Further, a feature of our invention is to disassociate signals and springjacks at the common point when certain predetermined lines become interconnected.

There are many other features.

Representation of apparatus in the accompanying drawings is diagrammatic and conventional and therefore does not purport to represent'actual structural details.

Our invention is subject to wide changes and adaptations in applying it to practical uses by those skilled in the art to which it belongs without departing from its scope. The descriptions and drawings therefore refor to one of many applications and adaptations of our invention which applications Specification of Letters Patent.

Patented June 1, 1920.

1915. Serial No. 34,182.

and adaptations are shown and described for purposes of. illustration and elucidation only.

In the accompanying drawings:

Figure 1 is a diagrammatic representation of equipment of a toll board at a station designated station A, Fig. 7, on a line designated line 1. Terminals of this equipment, A and B, correspond to similar designations in Fig. 7. Y

Fig. 2 is a diagrammatic representation of equipment at a toll board at a station designated station B, Fig. 7 ,"on a-line designated line 2. Terminals of this equipment, C and D, correspond to similar designations in Fig.7.

Fig. 3 is a diagrammatic representation of equipment at a toll board at a station designated station C, Fig. on a line designated line 3. Terminals of this equipment, 55 and 56, correspond to similar designations in Fig. 7.

Fig. 4 is a diagrammaticrepresentation of equipment at a toll. board at a station, designated station D Fig. 7. The terminals of this equipment I L, M, N, O, P correspond to similar designations in Fig.- 5. -An agency of said equipment is to enable oper ators at the stations A, B and C to obtain, at will, communication with either one of the other said stations, or any stations on the said lines.

Fig. 5 is a part of the circuit at station D. The terminals E, F and G, H, I and J correspond to the same letters in Fig. 4:, with a prime added. Terminals B and G correspond to B and G respectively, Fig. 4:. Terminals K, L, M, N, O, P correspond to the same letters in Fig. 4, with a prime added. It is possible to have the apparatus in Figs. 4 and 5 independent one of the other and connected by detachable. connections between the above terminals.

Fig. 6 is a diagrammatic representation of the essential elements of a common form of cord circuit suitable for connecting the springjacks shown with spring'jacks of independent lines, thus interconnecting the lines.

The methods of accomplishing the func- 105 tions constituted in the represented form of our invention may be outlined as -fol-' lows: Each station is provided with two sources of current-one having its positive pole grounded, therefore adapted to pro- 110 237 23s and 239-240;

ject a negative or minus current from its free terminal, and the other source of current having its negative pole grounded and therefore adapted to project positive or plus current from its free terminal. For convenience'of description we will refer to negative current as minus current and positive current will be referred to as plus current. Each station, as station A, station B and station O, is provided with three springjacks associated with theline extending to the common station D. Inserting a lug of a cord pair or set, as for instance D of the pair shown in Fig. 6, 1n springjack J Fig. 1, will project minus current from battery B derivedly to terminals A and -B. One path will be by way of upper winding of repeating coil 0 through contacts 13-12. The other fpath will be by way of lower winding 0 said repeating coil and contacts 16-17. Inserting said plug in springjack J will" project plus battery from battery B derivedly to terminals A and B. One path will be by wa of upper winding of repeating coil through contacts 26-25. The other path will be by way of lower winding of said repeating coil and contacts 29-30. ThlS current will enter station D in parallel over line 1 to terminals K and L respectively, station D, reaching ground G through center of repeating coil C by way of polarized relay R Designations to the right of said relay denote the direction of movement of the right end of its armature 230 when actuated by currents of polarities as designated at the arrows.

To illustrate the use of the apparatus shown, we will assume the operator at station A desires to call the common station D. The operator will insert a plug, such as P, into springjack J and manipulate listening key whereupon a telephonic circuit may be traced from'line terminals A and B through springs 1 and 4;, springjack J through tip and ring of plug P through contacts 301-302 and 303-304 of key M; through contacts 307-306 and 310-311 to the operators telephone circuit, the terminals of which are 300' and 301. If line 1 is not busy, due to its use by other stations, the operator signals by manipulating key k whereupon signal current flows from generator Z through contacts 300-301 and 305-304; through tip and ring of plug; through tip and ring of springjack J to line terminals A and B; over toll line conductors in series to terminals K and L, Fig. 5, and companion terminals K and L, Fig. 4; through contacts through contacts 242-243 and 24-245 to helix of line signal device D actuating said signal device and thus causing it to display, apprising the operator at stationD that her response is desired. Upon the response of the oper ator at station D, by inserting a plug similar to P into springjack J or J, Fig. 5, a circuit is established from the ground on the sleeve of the plug; through sleeve of springjack; through relay R to battery B", the current flowing actuates relay R and incidentally disassociates the line signal device D by opening contacts 242-243 and 244-2415; closing contacts 241-241. This completes a circuit from battery B through lamps 250 and 252 through contacts 241-241 to ground G, glowing the lamps. The glowing of the lamps will indicate to the other operators at station D that the line is in use at said station. After manipulating the listening key 10 a telephonic circuit is established from terminals K andL through tip and sleeve of springjack; through tip and ring of the'plug; through contacts 301-302 and 304-303; through contacts 307-306 and in multiple 210-311. Other operations of establishing be other stations on lines 1, 2 or 3 between If line 1 is free (there may.

the stations shown and station D, or there may bestations beyond or on extensions or legs of the respective lines), the operator removes plug from said springjack J and inserts it into springjack J Contacts 12-13 and 17-16 are made by the mechanical action of springjack springs J and J, which connect the line conductors through the center of repeating coil winding C to minus battery B causing minus current to flow over the line 1 to terminals K and L, Fig. 5; through center of repeating coil winding C through polarized relay R to ground G causing said relay R to operate in the indicated minus direction. This closes a circuit from ground G through contacts 208-207 to contact 195, and also through relay R to battery B Upon energization of relay R current flows through contacts 195-194 through relay R to battery B actuating said relay R. A circuit is also established from contact 208 through contacts 196-197; through remotion without breaking,

open, denergizing consequently, re-

drawing. The apparatus is the said plug lay R is to all operative purposes in an operated position. Current to ground G on contact 201 is connected with contacts 200-199-198, glowing busy or guard lamps 247, 249, 251, 253 and 255. Line No. 1 is now connected with line No. 2 as follows: inductively through the repeating coil windings C", C; through contacts 202-203 and 20-1-205; to line terminals M and N to toll line No. 2; to terminals and D, station B; through springjack contacts 35-34 and 32-33, to line signal device D The operator at station A signals by manipulating ringing key k Signaling current flows from generator- Z through contacts 6-7 and 11-10 to repeating coil windin C thence inductively to companion win ing 0; thence over circuit traced above to line signal device D causing it to display. The operator at station B responds by inserting plug as P into springjack J, incidentally cutting off the line slgnal device D and establishing a telephonic connection over the tip and ring of plug, tip and ring of springj ack to line, and thence to station R and R are actuated from same conductor as lamp 247 and actuate simultane ously with the glowing of said lamp, incidentally disassociating springjacks J J and J, J by the opening of contacts 237-238, 239-240 and contacts 262-263 and 264265 respectively. Subsequent operations of establishing a connection to independent lines follow the methods well known and common in the telephone art and need not be described. I

lVhen the operator at station A removes at the completion of the service, the current on the line and through'relay R is broken, relay R restores to its normal position as drawn. Current now flows from ground G through contacts 225-224; through contacts 206-207, to relay R". After relay R operates current flows throu h contacts 195-194 through relay R to attery B.- This actuates relay R and trips the latch 326, thus releasing relay R, which restores to its normal position as shown in the drawing. This incidentally opens contacts 206-207, deenergizing relays R and R, which also restore to their normal position as shown in the another call.

Since there are six sets of relays in Fig. 4: similar to those whose action is described above, and since the actions are almost identical in all, the above description-may be applied to all. Therefore, for the sake of brevit and clearness and for convenience in ma ing references, the similar relays and contacts are arranged in a parallel column below. Any difference in action will be noted in each particular case. it is not the previous case.

, connecting line A as traced above. Relays v contacts 26-25 and then ready for necessary, however, to refer to this table it the action of the set of relaysdescribed is kept in mind, as the corresponding relays can be readily traced from the drawings.

.Con-' Re- Con- Re- 110-. Renection. lay. tacts; lay. lay. 1ay. Lamps Lamps Lamps Line1to2. R21 228-229 R? an 3 I 2g; 247 Linc1 to3. R21 222-223 ew 11 24s I ine2to3. R 189-190 R" n 2f; 24s Line2tol. R" 183-184 R R" n 2%? if, 241 .Line3to1. a 143-144 a a B a Z 5: 24s Line3to2. R 149-150 a R" m v 22% 24s Assuming that the o erator at a station A on line 1 desires to ca 1 station C on line 3, the operator at said station A inserts plug as P into springjack J and listens in as in If line 1 is free, the-said operator removes plug from said springjack and "inserts it into springjack J incidentally 1 with plus batter from the center of repeating'coil'winding 5 through 29-30 to line; over line 1 to terminals K- and L; to relay R Relay R operates in the indicated plus direction followed by de endent relays R R and R in sequence, 26 being held in its operated position.

A telephonic circuit may be traced from springjack J through contacts 26-25 and 29-30, as above to linel; over line 1 to terminals K and L; inductively through repeating coil windings C and C through contacts 215-216 and 217-218; through contacts 232-233 and 236-235; to termi The operator at station A signals by manipulating key In, which connects generator Z through contacts 19-20 and 23-2 l to repeating coil windin C; thence through companion winding 3 of said coil to terminals A and B of line 1. 'The operator at station C responds by inserting a pin as P into springjack J or J". Current ows in circuit traced from grounded sleeve of said plug througli sleeve of said springj ack; through relay 5 actuating it and incidentally disassociating the line signal device D at contacts 110-111 and 112-113. Lamps 86, 87, 88, 89, 90 and 91 are caused to glow by The subsequent operations of establishing a of the interconnected lines is accomplished the closing of contacts 108-109..

coil Win by the withdrawing of the said plug from springjack J I Assuming that an operator at station B on line 2 desires to call station D, the 0 erator at station B will insert plug as 1 into springjack J. Subsequent operations including the responding of station D are the same as described for station A-calling said station D.

Assuming that an operator at station B on line 2-desiies-to call station Cfthe operator at station B wi 1 insert plug as P into springjack -J-". Minus current will flow from battery B through repeating coil winding C through contacts 42-41 and 38-37 to terminals C and D of line 2; thence over line 2 to terminals M and N; through relay R to ground G, actuating said relay R in the indicated minus direction. Relays R, R and R operate in sequence similar to previous description relating to relays R R and R relay R being held in its operated position. A telephonic circuit may be traced from the terminals M and N through condensers 153 and 154; through contacts 164-165 and 166-167; through contacts 232-233 and 235-236 to line terminals 0 and P; overline 3 to terminals 55 and 56; thence as rev'ously traced through line signal device B The 0 erator at station B signals with key M. he signal current passes inductively through repeating coil Winding C and C and current circuit is traced as before to line signal device D causing it to display. Subsequent operations are the same as described in description of station A calling station C.

Assuming that an.operator at station B on line 2 desires to call station A on line 1, the o iprator at said station B will insert plug as 1 into springjack J Plus current will fl'o'iv from battery B through repeating 'ng C; through contacts 45-44 and 48-49; to terminals C and D ofline 2; over line 2 to terminals M and N; through relay R to ground GT; causing relay R to operate in the indicated plus direction. Relays R R" and R operate in sequence similar to that of previous description, relay B being held in its operated position. The telephonic circuit may be traced from terminals M and N through condensers 153 and 154; through contacts 176-177 and 178-179 to terminals'L and K of line 1; thence to terminals A and B, etc. Subsequent operations are the same as described in description of station B calling station C.

Assuming that an operator at station C on line 3 desires to call station A, the operator at station will insert plug as P into either of springjacks J or J. Current will flow in circuit from grounded sleeve of plug; through sleeve of springjack; through relay B; through relay R to battery B,

current will flow from generator Z and also through contacts 63-64 and 62-61; through relay R to battery B, causing relays R R and R to operate.

inus current flows from battery B through contacts 79-80 to center of repeating coil winding C through contacts 68-67 and -71; to terminals 55 and 56 of line 3; to line terminals 0' and P; through relay R to ground G, actuating relay R in the indicated minus direction. Relays R, R and R operate in sequence, etc., relay R being held in its operated position. Belay R also operates through closing of contacts 122-123, introducing repeating coil windings C and C by making of contacts 234-235 and 231-232. The telephonic circuit maybe traced from line terminals 0 and P through contacts 234-235 and through repeating coil winding C; thence inductively to winding C through contacts 131-132; through condensers 151 and 152; through contacts 1 24-125 and 126-127, to terminals K and L of line 1, to terminals A and B, etc., as described in description of station B callingstation A. The operator at station C signals by manipulating key it. Signal through contacts previously described through'tip and ring of plug; through tip and ring of springjack; through terminals 60-59 and 58-57; through relay R causing its armature to vibrate in conformance with alternations of signaling current. This opens contacts 63-64 and 62-61 alternately and allows relay R to restore to its normal position during the duration of the. time signaling current is applied. current then flows through contacts 74-7 5 and 77-78; through winding C of repeating coil; thence inductively to winding C through contacts 67-68 and 69-70 to line terminals 55 and 56; thence over line 3 to terminals A 'and B, etc., as previously traced to line signal device D Subsequent operations are the same as described in description of station B calling station A. 7

Assuming that an operator at station 0 on line 3 desires to-call station B, the 0 erator at station C will insert plug as 1 auto springjack J or J. Current will ow plug; through sleeve of springjack; through relay R to battery B", causing said relays R and R to operate as in the last description above. It will be noted that the only difference is that relay B does not operate, and with this exception the description of signaling and the course of telephonic currents may be applied to this case. Plus current flowsfrom battery B through the center of repeating coil windings C etc., as previoi'lsly traced to line, and through relay R to ground G causing relay R to oper- Signaling n circuit from. grounded sleeve of ate in the indicated plus direction. Relays R, R and R operate in sequence, as in similar previous description; likewise relay R will operate, relay B being held in its operated position. A telephonic circuit may be traced through repeating coil windings C and C, as in the last description above; thence through condensers 151-152; through contacts l36137 and 138-139, to the terminals M and N of line 2; over line 2 to terminals C and D; to springjacks J* and signal device D Subsequent operations are the same as described in description of station A calling station B.

Assuming that operator at station D desires to call station A, the operator at station D will insert plug as P into either of springjacks J or J. Current will flow in circuit from grounded sleeve of plug; through sleeve of spyingjack; through relay R actuating said relay and incidentally disassociating signal device D by opening of contacts 242-243 and 244-245. The operator at station D signals with key k as previously described. The telephonic circuit may be traced from tip and ring of springjack through contacts 239-240 and 238237 to terminals K and L of line 1; over line 1 to terminals A and B; thence to signal device D Subsequent operations at station A are the same as described in description of station B calling station A.

Assuming that operator at station D desires to call station B, the og rator at station D will insert plug as 1 into either of springjacks J or J", causing relay R to operate incidentally disassociating signal device D from line 2. The telephonic circuit may be traced from tip and ring of springjack through contacts 264265 and 2(5;-2G3 to terminals M and N of line 2; over line 2 to terminals Cvand D; thence to signal device D Subsequent operations at station B are the same as described in description of station A calling station B.

Assuming that operator at station D desires to call station C, the operator at station D will insert plug as P into either of springjacks J or J causing relay R to operate, thus disassociating signal device D from line 3. The telephonic circuit may be traced from tip and ring of springjack; to terminals 0 and P of line 3; over line' 3 to terminals 55 and 56; thence to signal device D Subsequent operations at station C are the same as described in description of station B calling station C.

Two springjacks are shown associated in each group of springjacks corresponding to the three functions of interswitching, Fig. 3. It is not necessary to limit the number to two springjacks in each group, but that any plurality of springjacks can be employed as found convenient to permit access to lines by a number of separated operators at any station. The same applies to the springjacks shown in Fig. 5.

Also, the signals shown may be the common form of lamp signal or electromagnetic signal. These may be changed within wide limits it found desirable.

Also, in the foregoing specification mention is made of the current passing over the lines 1, 2 and 3 in parallel. It is not essential that the currents for operating the various relays shall pass over both Wires of the line, but by employing well known methods one limb of the circuit only may be employed to convey these currents, leaving the remaining limb in each case for other uses.

Having thus described our invention, what we claim as new and desire to secure by .lnited States Letters, Patent is:

1. The combination of a plurality of lines entering a common station; a remote station on each of said lines; as many springjacks connected to a said line at each of said re mote stations as there are lines entering said common station; a switching plug at each station adapted to use in said springjacks; means whereby inserting said plug into any of said springjacks will cause the line with which it is associated to become connected with a predetermined line entering the common station; a springjack at each said station for service to'the common station.

2. The combination of a plurality of lines entering a common station; a remote station on each of said lines; as many springjacks connected to a said line at each said remote stations as'the number of lines it is desired to connect a said line with, line connectin relays at the common station; means at eac said remote station for causing the actuation of a relay at said common station associated with the line leading from the calling remote station and corresponding to a said springjack, said relay adapted to connect said calling line to a predetermined called line entering the common station.

3. The combination of three lines entering a common station; remote stations on said lines: three springjacks associated with said lines at each said remote station; line connecting relays at the common station, a first said springjack adapted upon a switching plug registering with same to cause a first relay at said common station to actuate to close a telephonic circuit between said line and a first predetermined line of said lines; a second of said springjacks adapted upon a switching plug registering with same to cause a second relay at said common station to actuate to close a telephonic circuit between said line and a second predetermined line of said lines; athird of said springjacks adapted for independent service on the line leading to said springjack.

l. A plurality of lines entering a common tion controlled bythe first relay, a third re- ,lfay controlled by the second relay adapted to connect said first line with a predetermined line entering said common station, the

" actuation of said third relay causing the said second relay to restore to normal position, the second relay in turn incidentallydenergizing said third relay, and a mechanical connection between the first and second relays for holding the first relay in 1;energizing position with the lines connected. v5. A plurality of lines entering a common station, a remote station on the first line, a polarized relay at said common station diff ferently operable for connection with either.

one of two other lines,'two independently operable line connecting relays for connecting the first line. with said two other lines and actuated according to the operation of the polarized relay, means for mechanically interrupting the energizing circuit of the locked relay. 7

6. A plurality of lines entering a common station; a remote station on a first said line;

a first relay at said common station under control of said remote station, asecond relay at said common station controlled by v the first, a third relay controlled by the second relay and adapted to connect said first line with a predetermined line entering said common station, the actuation of said third relay causing the said second relay to restore to normal position, the said second relay in turn incidentally de'c'nergizing said third'relay; and a mechanical connection between said second and third relays for' holding the third relay in energizing position with the lines connected. f

7. ,At a connecting point a first relay under control of 'a remote station; a-s'econd re lay under control of said first relay; a third relay under control of said second relay, said third relay adapted to cause two predetermined lines to be connected together. said third relay also adapted to cause said second relay to return to normallposition and said second relay adapted to in turn' cause said third rela to become del nergizcd; upon said-second re ay returning to normal, position; a mechanical device between said second and third relays which will hold said third relay in an actuated position with lines connected means at said remote station for causing a second. actuation of said first relay which in turn will cause the actuation of said second relay, said latter actuation destroying the eifective relation of the said mechanicaldevice so said third relay will return to normal position with said lines unconnected.

8. At a connecting point a first relay under control of a remote station; a second relay-under control of said first relay; a third relay under control of said second relay, said third relay adapted to cause two predetermined lines-to be connected together, said third relay also adapted to. cause said second relay to return to vnormal position and-said second relay adapted to in turn cause said third relay to become denergized upon said second relay returning to normal position; a mechanical device between said second andthird relays which will hold said third relayin an actuated position with lines connected; means at said remote station for causing the said third relay to return tonorzjnal.

:9. At a connecting point a first relay under control of a remote station; a second relay under control of said first relay; a

third relay under control of said second relay, said third relay adapted to cause predef termined lines to-be connected together, said locking the line connecting v;;relays in ac-' ,tliated position, and means for thereafter third relay also adapted to cause said second relay to return to normal position and said second relay adapted to in turn cause said third rel'a to become deenergized upon said second relliy returning to normal position and a mechanical device between said second and third relays which will hold said third relay in an. actuated position with lines connected.

10. A first polarized relay adapted to close independent circuits responsive to each polarity of energizing current ap liedtheret'o; a second relay under control 0 said first relay; a third relay under control of said secondrelay; a mechanical locking device form- ..,.ing a part of the moving elements of said second and third relays; said second relay adapted to return to normal position upon [the actuation of said third relay and said close independent circuits responsive to each polarity; of energizing current applied; a second rela under control of said first relay; a thir relay under control of said second relay; a mechanical device forming a part of the moving elements of said second and third relays; saidvsecond relay adapted to return to normal position upon the actuation of said third relay and said third relay adapted to in turn deenergize upon said second relay returning to normal position, said mechanical device so registering that said third relay is retained in an opond relay under relays actuated position mechanically upon the reerated position upon said second relay returning to normal position,

P larity to reactuate said second relay and release to normal position said third relay.

12. A first polarized relay adapted to close independent circuits responsive to each polarity of energizing current applied; a seccontrol of said first relay; a third relay under control of said second relay; a mechanical device forming a part of the moving elements of said second and third relays; said second relay adapted .to return to normal position upon the. actuation of said third relay and said third relay adapted to in turn deenergize upon said second relay returning to normal position, said mechanical device so registering that said third relay is retained in an operated posi-. tion upon said second relay returning to normal position, said first relay adapted upon energizing with reversed polarity to reactuate said second relay and release to normal position said third relay, the said third relay adapted to interconnect a plurality of predetermined lines'during the time it is in an actuated position. 1 13. The combination of a plurality of lines entering a common station; a remote station on a first said line; means at said remote station for applying current of a first and a second polarit at will; a relay at said common station sive to said polarities of current, said relay controlling a second relay upon its actuation conforming to said first polarity, said second relay in turn controlling a third relay, said third relay in turn causing said second relay to return to normal position upon the actuation of said third relay; a device forming a part of second and third for retaining said third relay in an turn to normal position of said second relay and the incidental deenergization of said third relay thereby; a circuit relationship between the contacts of said relays such that when said second current polarity is applied to said relay causing its actuation conforming therewith said second relay will actuate to mechanically release to normal position said third relay.

14. The combination of a pluralityyof lines entering a common station; a remote station on a first said line; means at said remote station for applying current of a first and second polarit at will; a relay at said common station diflt'erently to said polarities of current, sald relay controlling a second relay upon its actuation conformin to said first polarity, said second relay in turn controlling a third relay, said third relay in turn causing said second relay to return to normal position-upon the actuation of said third relay; a device formsaid first relay adapted upon energizing with reversed ifierently respon' responsive "ing a part of said second and third relays rela adapted 'to interconnect a plurality of pre etermined lines.-

15. "The combination of three lines entering a. common station; a remote station on a first said line; relays at the common station, means at said remote station for controlling a first relay at said common station which is adapted to connect together predetermined lines upon it being in an actuated position; a signal lamp at said common station and a second relay controlling access to said first line from said common station under control of said first relay; the said lamp adapted to glow and the said second relay adapted' to prevent access to said line during the time said first relay is in an actuated position. v i I 16. The combination of three lines enteringl a common station; a remote station on a rst said line; relays at a common station, means at said remote station for controlling a first relay at said commonstation adapted to connect together predetermined lines upon it being in an actuated position; a signal lamp at said common station and a second and thirdrelay controlling access respectively to said first line and the predetermined line with which it is adapted to be connected by said first relay, the said lamp adapted to glow and the said secondand third relays adapted to prevent access to said first line and the line with which it is connected during the time said first relay with another upon glowing indicating that a specific two lines are connected,

18'. The combination of three lines entering a common statlon; relays on each said line for connecting the specific line with apredetermined line; signal lampsassociated with the relays which will 'glow when two said lines are connected, each said lamp glowing being indicative of two definite lines being connected.

19. At a connecting point three lines adapted to be connected one with another at will through'the agency of two relays on each line at said connecting points, the firs; Y

of said relays adapted to connect its associated line to a second line andthe second of said relays adapted to connect its line to a thirdllne; three signal devices with a free pole of each common to contacts of two said relays, mate contacts so disposedthat the actuation of any said relay connecting any two lines will incidentally cause a said signal device to actuate indicative of which two lines are connected.

20. At a connecting point a first line adapted to be connected to a second or third line at will through the agency of specific relays thereforja second line adapted to be connected to said first or said third line at will through the agency of specific relays therefor; said third line adapted to be connected to said first or said second line at will through the agency of specific relays therefor; three signal devices so associated with auxiliary circuits of said relays that a specific said device will actuate upon any 'Sflld relay actuating incidental to connecting any two lines, the actuation of a said signal device indicating a connection be tween a specific two lines.

21. At a connecting point lines adapted to be connected, relays controlled over calling lines and each specific to the two lines to be connected; a repeating coil, an auxiliary relay associated with a calling line adapted to introduce all the windings of the repeating coil into said line, 'sald relay under control of the relay adapted to connect said line with a second line.

'22. At .a connecting point a calling line adapted to be connected to any one of a plurality of lines; means controlled over the calling line to effect such connection, a repeating coil, 'electro-magnetic means controlled over a calling line adapted toconnect all the windings of the repeating coil into said calling line, said means operative when said first line is connected with a predetermined line of said plurality of lines.

23. In a telephone system, a subscribers telephone line terminating at a connecting statlon, spring jacks for the line at said station, a normally disconnected repeating repeating coil into the line circuit.

24. In a telephone system, a telephone line extending from an operators station to'a n interconnecting station, a second telephone line extending from the interconnecting station, spring jacks for the first line at the operators station, a repeating coil for the first line, a plug ended cord circuit, means whereby the operator may connect with the near line through one spring jack and with the far line through another spring jack, and means whereby made with one of the two lines said repeating coil is connected into the line circuit.

25. In a telephone system, three telephone lines terminating at a common station, remote stations on each line, a calling signal for each line at the common station, means at the common station controlled from a remote station for connecting the line of the remote station with, either one of the other two lines and for disconnecting the calling signals of the connected lines at the common station, and a signal lamp at the common station operative to indicate that a connection exists between the two lines. 7

26. In a telephone system a plurality of lines entering a common station, relay mechanism for interlinking said lines interchangeably and lamp signals controlled by said relay mechanism at said common station, one specific to each possible connection, each lamp indicating that its corresponding two lines are connected.

Signed b us at Portland, county of Multnomah, and State of Oregon, in the presence pflgwo witnesses, this fifth day of June,

HERBERT M. FRIENDLY. ARCHIBALD E. BURNS.

when connection is soas to connect any'two lines, 

